Terminal Block, Connection Apparatus Formed Therewith, and Field Device with such a Connection Apparatus

ABSTRACT

A terminal block serves for electrically connecting a connection line and extending externally of an electronics housing. The terminal block comprises a platform composed at least partially of an electrically insulating, synthetic material, a connection terminal arranged on a first side of the platform forming a first connection side of the terminal block and serving for connection of a conductor of the connection line as well as at least one connection terminal arranged on the first side of the platform. A connection contactor. Arranged within the platform, especially for the purpose of forming a circuit output meeting European standard EN 60947 5 6:2000, are a resistance element as well as a resistance element. A first connection of the resistance element is electrically connected with the connection terminal and a second connection of the resistance element is electrically connected with the connection contactor.

The invention relates to a terminal block for electrically connecting aconnection line having at least two conductors as well as to aconnection apparatus formed with such a terminal block for electricallyconnecting a field device circuit accommodated in an electronics housingwith a connection line extended externally of the electronics housing.Furthermore, the invention relates to a field device having such aconnection apparatus, for example, a field device embodied as ameasuring and/or switch device.

Applied in industrial process measurements technology, especially alsoin connection with the automation of chemical processes or proceduresfor producing a product from a raw or starting material by use ofchemical, physical or biological processes and/or the automated controlof industrial plants, are so-called field devices, namely electricalmeasuring and/or switch devices installed directly at the respectiveplant. Such devices include e.g. Coriolis, mass flow, measuring devices,density measuring devices, magneto inductive, flow measuring devices,vortex, flow measuring devices, ultrasonic, flow measuring devices,thermal, mass flow measuring devices, pressure measuring devices, filllevel measuring devices, fill level limit switches, temperaturemeasuring devices, pH-value measuring devices, etc., which serve forproducing process variables—analog or, for example, also digitalvariables—representing measured values as well as for producing themeasured value signals lastly carrying such variables. The processvariables respectively to be registered can include, depending onapplication, for example, a mass flow, a density, a viscosity, a filllevel or a limit level, a pressure or a temperature or the like, of aliquid, powdered, vaporous or gaseous medium, which is conveyed,respectively held, in a corresponding container, such as e.g. a pipelineor a tank.

For registering the respective process variables and for transducing thesame into an electrical measurement signal corresponding thereto, fielddevices have a corresponding physical to electrical or chemical toelectrical, measuring transducer, which is most often mounted directlyin a wall of the container containing the medium or in the course of aline, for example, a pipeline, conveying the medium.

For processing the measurement signal, the measuring transducer isfurther connected with a measuring device internal, operating andevaluating circuit provided in an electronics of the field device andserving for further processing or evaluating the at least onemeasurement signal, as well as also for generating correspondingmeasured values. Examples of such measuring systems known, per se, tothose skilled in the art are disclosed in WO-A 88/02853, WO-A 88/02476,U.S. Pat. No. 6,452,493, US-A 2011/0317390, EP-A 816 807, EP-A 1 591 977or DE-A 10 2008 052 912, respectively available from the applicant, forexample, under the marks FLOWPHANT® DTT31, t-switch ATT11, t-trendATT12, Magphant DTI200, Promag 53H, Prowirl 73F, Promass 83X, or Promass84F.

The particular electronics of the respective field device is, mostoften, accommodated in a comparatively robust, for instance, impact-,pressure-, explosion- and/or weather resistant, electronics housing. Theelectronics housing can be arranged e.g. removed from the field deviceand connected with such only via a flexible cable; the electronicshousing can, however, also be arranged directly on the measuringtransducer or on a measuring transducer housing separately housing themeasuring transducer.

In the case of a large number of field devices used in industrialmeasurements technology, the measuring transducer is so driven at leastat times by a driver signal generated by the operating and evaluatingcircuit for producing the measurement signal during operation that itacts in a manner suitable for the measuring at least indirectly or, viaa probe directly contacting the medium, practically directly on themedium, in order to bring about reactions corresponding to the measuredvariable to be registered. The driver signal can, in such case, becorrespondingly controlled, for example, as regards an electricalcurrent level, a voltage level and/or a frequency. Examples of suchactive measuring transducers, thus measuring transducers correspondinglyusing an electrical driver signal, include, especially, flow measuringtransducers serving for measuring media flowing at least at times, e.g.measuring transducers with at least one coil driven by the driver signalfor producing a magnetic field or with at least one ultrasonictransmitter driven by the driver signal, or, however, also fill leveland/or limit level transducers serving for measuring and/or monitoringfill levels in a container, such as e.g. transducers with a freelyradiating microwave antenna, a Goubau line or a vibrating, immersionelement.

The measured values generated by the operating and evaluating circuitare provided at corresponding circuit outputs in the form ofelectrical—digital or analog—measured value signals, for example, in theform of an analog signal current correspondingly modulated in the rangeof 4-20 mA. Moreover, also usual for providing measured values areso-called frequency outputs, namely circuit outputs coding the measuredvalues in a pulse sequence frequency of a binary, rectangular signal, oralso so-called pulse outputs, namely circuit outputs in the form of apulse signaling the reaching of an earlier selectable measure ofquantity. Besides field devices with measuring transducers servingprincipally for registering a physical or chemical variable, there areadditionally also field devices embodied, for example, as electric motordriven, actuator valves or pumps, which are provided, especially, foradjusting one or more physical, process parameters, consequentlyactively interacting with the respective process, supplementally,however, also making available internal, measuring and/or setting valueson corresponding circuit outputs.

Besides circuit outputs of the aforementioned type providing measuredvalues, modern field devices can, at times, also have so-called status,respectively alarm, outputs and/or also circuit outputs serving fordirectly activating external electrical devices, such as relays,directly connected to the field device. Such circuit outputs can beimplemented as passive circuit outputs, namely in the form of a circuitoutput forming part of an electrical circuit driven by a voltage sourcestationed externally of the field device, or also as active circuitoutputs, namely in the form of a circuit output forming part of anelectrical circuit driven by a voltage source internal to the fielddevice. Alternatively or supplementally, field devices can also havecircuit outputs for connecting to a fieldbus, for example, a serialfieldbus.

For connecting internal electronic circuits, not least of all alsocircuits having circuit outputs of the initially mentioned type, withone or more external electrical circuits, field devices have most oftenconnection systems formed by means of a terminal block for electricallyconnecting a connection line of two or more conductors brought from theexterior to the field device.

Field devices of the type being discussed have, from time to time, oneor more electrical circuit outputs, whose operation, respectively whoseelectrical parameters, such as, for instance, a particular outputimpedance, respectively a particular terminating resistance, can also beconfigured by the user, respectively on-site, suitably for a respectiveapplication. Representative of such configurable circuit outputs offield devices are, for example, the mentioned circuit outputs, formed,for example, by means of a bipolar transistor with “open” collectorconnection (open collector) or by means of a field effect transistorwith “open” drain connection (open drain), for binary switching signalsor also pulse outputs of binary clock signals. As a rule, these musthave namely only two switch states sufficiently separated as regards arespectively flowing electrical current, thus provide only asufficiently large and as constant as possible difference between theelectrical current flow allowed respectively in the switch state forlogic “0” (LOW) and that in the switch state for logic “1” (HIGH). Forthe special case, however, that said switch output should, for instance,be configured as a passive circuit output conforming to the Europeanstandard EN 60947-5-6:2000, it is additionally also to be assured thatin the case of the connection conditions specified in said standard theelectrical current flow in the switch state for logic “0” have anelectrical current level, which lies within a therefor predeterminedinterval of 0.1 mA to 1 mA, and the electrical current flow in theswitch state for logic “1” have an electrical current level, which lieswithin a predetermined electrical current interval of 2.2 mA to 8 mA.This can be achieved, for example, by connecting to the circuit outputhaving a first connection at a first connection terminal of the terminalblock supplementally a series resistance, for example, in the order ofmagnitude of 1 kΩ, for limiting the maximum electrical current, as wellas between a first connection either with the first connection terminalor with a second connection of the series resistance and a secondconnection with the second connection terminal a parallel resistance,for example, in the order of magnitude of 10 kΩ, achieving the minimumelectrical current for logic “0”. If the standard does not have to bemet, then the two resistances do not have to be provided.

For the purpose of bringing about such initial settings of functions orcomponents, there are provided in conventional field devices most oftenshort-circuiting plugs, so-called jumpers, for the selective connectingof circuit elements or also so-called DIP switches for the selectiveconnecting, respectively disconnecting, of paths of the respectiveelectronic circuits, wherein said short-circuiting plugs, respectivelyDIP switches, are, not least of all for reasons of space and cost,arranged most often in the immediate vicinity of the respectivecomponents, consequently directly on a circuit board carrying theparticular circuit and in the immediate neighborhood also of othercomponents of the electronic circuit. Although such adapting of circuitoutputs by means of short-circuiting plugs, respectively DIP switches,must most often be performed only once or only very seldom, forinstance, in the course of the initial electrical connecting of therespective field device to an external connection line, nevertheless anot insignificant risk is associated therewith that the electronics willbe damaged thereby, for instance, as a result of electrostatic chargesor mechanical effects.

Taking this into consideration, an object of the invention is to providea connection system for a circuit output of an electronic circuit of afield device, respectively a terminal block therefor, whereby anaccessing from the exterior into said circuit for the purpose ofconfiguring the circuit output, for example, also for the purpose of asubsequent configuring on-site, for a circuit output meeting Europeanstandard EN 60947-5-6:2000 can be avoided.

For achieving the object, the invention resides in a terminal block forelectrically connecting a connection line having at least twoconductors, for example, a connection line extending externally of anelectronics housing. The terminal block of the invention comprises aplatform composed at least partially of an electrically insulating,synthetic material, for example, a synthetic material having andielectric strength sufficient to meet European standard EN 60947-1, forexample, a synthetic material in the form of a plastic, a firstconnection terminal arranged on a first side of the platform forming afirst connection side of the terminal block and serving for connectionof a first conductor of the connection line, at least a secondconnection terminal arranged on the first side of the platform,laterally spaced from the first connection terminal and serving forconnection of a second conductor of the connection line, a firstconnection contactor arranged on a second side of the platform forming asecond connection side of the terminal block, for example, a firstconnection contactor embodied as a contact pin or as a contact jack, asecond connection contactor arranged on the second side of the platformand laterally spaced from the first connection contactor, for example, asecond connection contactor embodied as a contact pin or as a contactjack, a first resistance element arranged within the platform, forexample, a first resistance element also embedded in synthetic material,wherein a first connection of the first resistance element iselectrically connected with the first connection terminal and a secondconnection of the first resistance element is electrically connectedwith the first connection contactor, as well as a second resistanceelement arranged within the platform, for example, a second resistanceelement embedded in synthetic material, wherein a first connection ofthe second resistance element is electrically connected with the firstconnection terminal or with the first connection contactor and a secondconnection of the second resistance element is electrically connectedboth with the second connection terminal as well as also with the secondconnection contactor.

Moreover, the invention resides also in a connection apparatus with sucha terminal block for electrically connecting a field device circuitaccommodated in an electronics housing with a connection line extendingexternally of the electronics housing, wherein the connection apparatusof the invention comprises besides said terminal block a connection basefor the terminal block, wherein the connection base is composed at leastpartially of an electrically insulating, synthetic material, forexample, a synthetic material in the form of a plastic.

Furthermore, the invention resides in a field device, for example, afield device formed as a measuring and/or switch device, comprising sucha connection apparatus and an electronic circuit electrically connectedwith said connection apparatus.

In a first embodiment of the terminal block of the invention, it isprovided that the first resistance element has an ohmic resistance ofgreater than 0.9 kΩ and less than 1.1 kΩ.

In a second embodiment of the terminal block of the invention, it isprovided that the second resistance element has an ohmic resistance ofgreater than 9 kΩ and less than 11 kΩ.

In a third embodiment of the terminal block of the invention, it isprovided that the second resistance element has an ohmic resistance,which is greater than 9-times an ohmic resistance of the firstresistance element and less than 11-times the ohmic resistance of thefirst resistance element.

In a first embodiment of the connection apparatus of the invention, theconnection base comprises a platform composed at least partially of anelectrically insulating, synthetic material, a first connectioncontactor arranged on a first side of the platform forming a firstconnection side of the connection base and complementary to the firstconnection contactor of the terminal block, as well as at least a secondconnection contactor arranged on the first side of the platform,laterally spaced from the first connection contactor and complementaryto the second connection contactor of the terminal block.

In a second embodiment of the connection apparatus of the invention, itis provided that connection base and terminal block are mechanicallyconnected with one another to form a pluggable, for example, alsoreleasable, galvanic connection between the first connection contactorof the terminal block and the first connection contactor of theconnection base as well as between the second connection contactor ofthe terminal block and the second connection contactor of the connectionbase.

In a third embodiment of the connection apparatus of the invention, itis provided that each of the two connection contactors of the connectionbase is electrically connected, for example, by material bonding, with aline of an electronic circuit, for example, a line formed as aconductive trace on a circuit board.

In a first embodiment of the field device of the invention, it isprovided that the electronic circuit has two connection contactorsembodied, for example, in each case, at least sectionally as aconductive trace on a circuit board and/or at least sectionally asconductive wire, wherein a first connection contactor of the twoconnection contactors is electrically connected with the firstconnection contactor of the connection base and a second connectioncontactor of the two connection contactors is electrically connectedwith the second connection contactor of the connection base, forexample, by means of soldered connections.

In a second embodiment of the field device of the invention, it isprovided that the electronic circuit has a circuit output, for example,one formed by means of a transistor and/or a passive circuit output,with a first output contactor electrically connected with the firstconnection contactor of the connection base and with a second outputcontactor electrically connected with the second connection contactor ofthe connection base. Developing this embodiment of the inventionfurther, it is, additionally, provided that, by means of the circuitoutput, the connection base and the terminal block, a switch outputmeeting the European standard EN 60947-5-6:2000 is formed.

In a third embodiment of the field device of the invention, it isprovided that the electronic circuit has a bipolar transistor with acollector connection and with an emitter connection. Developing thisembodiment of the invention further, it is, additionally, provided that,for instance, for forming a circuit output meeting European standard EN60947-5-6:2000, the collector connection of the bipolar transistor iselectrically connected with the first connection contactor of theconnection base, consequently via the first resistance element with thefirst connection terminal of the terminal block, and the emitterconnection of the bipolar transistor is electrically connected with thesecond connection contactor of the connection base, consequently withthe second connection terminal of the terminal block.

In a fourth embodiment of the field device of the invention, it isprovided that the electronic circuit has a field effect transistor witha source connection and a drain connection. Developing this embodimentof the invention further, it is, furthermore, provided that, forinstance, for forming a circuit output meeting European standard EN60947-5-6:2000, the drain connection of the field effect transistor iselectrically connected with the first connection contactor of theconnection base, consequently via the first resistance element with thefirst connection terminal of the terminal block, and the sourceconnection of the field effect transistor is electrically connected withthe second connection contactor of the connection base, consequentlywith the second connection terminal of the terminal block.

In a first further development of the field device of the invention,such additionally comprises an electronics housing, within which boththe connection apparatus as well as also the electronic circuit areaccommodated.

In a second further development of the field device of the invention,such additionally comprises a measuring transducer for producing atleast one measurement signal dependent on a physical, measured variableto be registered.

According to a basic idea of the invention, additional resistancesrequired for configuring circuit outputs of electronic circuits of fielddevices, for instance, for forming a circuit output meeting Europeanstandard EN 60947-5-6:2000, namely resistances addable, respectivelyremovable, by means of short-circuiting plugs or DIP-switches, are notsuch as previously done, arranged directly on a circuit board, whichbears the particular electronic circuit, respectively the electroniccomponents forming its output, but, instead, are accommodated separatedtherefrom in a special terminal block connected via a connection basereleasably with the remaining components of the electronic circuit. Anadvantage of the invention is, among other things, that said terminalblock can, in turn, be replaced very simply with another terminal block,in given cases, even a terminal block without resistances or a terminalblock with resistors having other resistance values, for example, evenin the case of field devices already installed on-site, or, conversely,for instance, in the case that after installation of the field device aconfiguring of the circuit output according to European standard EN60947-5-6:2000 is required, in which case said circuit output can beretrofitted very simply by means of a special terminal block containingthe corresponding resistances.

The invention as well as other advantageous embodiments thereof will nowbe explained in greater detail based on examples of embodimentspresented in the figures of the drawing. Equal parts are provided in allfigures with equal reference characters; when perspicuity requires or itotherwise appears sensible, already mentioned reference characters areomitted in subsequent figures. Other advantageous embodiments or furtherdevelopments, especially also combinations of initially onlyindividually explained aspects of the invention, will become evident,furthermore, from the figures of the drawing, as well as also from thedependent claims per se. The figures of the drawing show as follows:

FIG. 1 schematically, a field device embodied, for example, as anindustrial measuring and/or switch device;

FIG. 2 schematically, a variant of a terminal block suitable for thefield device of FIG. 1; and

FIG. 3 schematically, a variant of a circuit output suitable for thefield device of FIG. 1.

FIG. 1 shows, schematically, a field device with an electronic circuit30 accommodated within an electronics housing H. Electronic circuit 30is formed at least partially by means of semiconductor elements. Thefield device can be embodied, for example, as a measuring and/or switchdevice suitable for industrial automation technology and/or, such asindicated in FIG. 1, can have a measuring transducer S connected to thecircuit 30 and serving for producing at least one measurement signals_(x) dependent on a physical, measured variable x to be registered.

Electronic circuit 30 includes a circuit output 30A, for example, oneformed by means of a transistor, having a first output contactor A1 anda second output contactor A2. Each of the two output contactors A1, A2can be embodied e.g., at least sectionally, as a conductive trace on acircuit board 300 at least partially carrying the electronic circuit 30and/or, at least sectionally, as a conductive wire. Circuit output can,in turn, be, for example, a frequency output for outputting a binary,rectangular signal having a pulse sequence frequency representing themeasured variable x, respectively its time curve, and encoding measuredvalues, or it can be, for example, a pulse output for outputting pulses,which signal the reaching of an earlier selectable size of the measuredvariable x. The circuit output can, however, for example, also beconfigured as a status- or alarm output and/or also serve for the directactivating of external electrical devices connected to the field device,consequently serving as a relay actuator. The circuit output can, forexample, also be a passive, switch output or, however, also be adaptedas a connection to a fieldbus, for example, a serial fieldbus.

In the example of an embodiment shown in FIG. 1, circuit output 30A is,for example, for the purpose of forming an open collector output, formedby means of a bipolar transistor, wherein a collector connection of thebipolar transistor forms the connection contactor A1 of the electroniccircuit 30 and an emitter connection of the bipolar transistor forms theconnection contactor A2 of the electronic circuit 30. Alternatively orin supplementation, the circuit output 30A can, such as schematicallypresented in FIG. 3, be formed, for example, also by means of a fieldeffect transistor with a source connection and a drain connection, forexample, in such a manner that, for forming an open drain output, thefirst connection contactor A1 of the electronic circuit 30 is formed bymeans of the drain connection and the second connection contactor A2 ofthe electronic circuit 30 is formed by means of the source connection.

For electrically connecting the circuit output 30A, consequently theelectronic circuit 30, with a connection line extending externally ofthe electronics housing H, there is provided in the field device,furthermore, a connection apparatus electrically connected with thecircuit 30 and having a terminal block 10 for such a connection line aswell as a connection base 20 for the terminal block. Connection base 20is composed at least partially of an electrically insulating, syntheticmaterial, for example a plastic.

Terminal block 10 includes a platform 100 composed at least partially ofan electrically insulating, synthetic material, for example, one havinga dielectric strength sufficient to meet European standard EN 60947-1.Arranged on a first side of the platform 100 forming a first connectionside of the terminal block 10 is a first connection terminal T1 for afirst conductor L1 of a connection line, as well as, laterally spacedfrom the first connection terminal, at least a second connectionterminal T2 for a second conductor L2 of the connection line. Arrangedon a second side of the platform forming a second connection side of theterminal block 10 are additionally a first connection contactor J1, forexample, one embodied as a contact pin or contact jack, as well as,laterally spaced from the first connection contactor, a secondconnection contactor J2, for example, one embodied as a contact pin orcontact jack.

The connection base 20 forming for practical purposes a receptacle forthe terminal block 10 includes likewise a platform 200 composed at leastpartially of an electrically insulating, synthetic material, forexample, the same synthetic material as that of the platform 100 of theterminal block 10. Arranged on a first side of the platform 200 forminga first connection side of the connection base 20 are, consequently, afirst connection contactor 91 complementary to the connection contactorJ1 of the terminal block 10 as well as, laterally spaced from saidconnection contactor 91, a connection contactor P2 correspondinglycomplementary to the connection contactor J2 of the terminal block 10′.Each of the two connection contactors P1, P2 of the connection base can,such as schematically shown in FIG. 1, each be directly electricallyconnected with the respectively complementary output contactor A1,respectively A2, of the electronic circuit 30, for example, by means ofmaterial bonded, soldered connections. Output contactors A1, A2 areformed, for example, as conductive traces on a circuit board 300.

Especially, terminal block 10 and connection base 20 are, furthermore,adapted (while forming, for example, based on a plugged contact, agalvanic connection between the connection contactor J1 of the terminalblock 10 and the complementary connection contactor P1 of the connectionbase 20 as well as between the connection contactor J2 of the terminalblock 10 and the complementary connection contactor P2 of the connectionbase 20) to be able to be connected mechanically with one another,especially releasably, respectively to be correspondingly connected withone another.

For the mentioned case, in which the circuit output 30A is formed bymeans of a bipolar transistor, so that the connection contactor A1 isformed by means of a collector connection and the connection contactorA2 is formed by means of an emitter-connection, then, as a result, asdirectly evident from FIG. 1, the collector-connection of the bipolartransistor is electrically connected with the connection contactor P1 ofthe connection base, consequently via first resistance element R1 withthe connection terminal T1 of the terminal block, respectively theemitter connection of the bipolar-transistor is electrically connectedwith the connection contactor P2 of the connection base, consequentlywith the connection terminal T2 of the terminal block. For the othermentioned case, in which the circuit output 30A is formed by means of afield effect transistor, so that the connection contactor A1 is formedby means of a drain connection and the connection contactor A2 is formedby means of a source connection, then, as a result, as directly evidentfrom FIG. 3, the drain connection of the field effect transistor iselectrically connected with the connection contactor P1 of theconnection base, consequently via resistance element R1 with theconnection terminal T1 of the terminal block, respectively the sourceconnection of the field effect-transistor is electrically connected withthe connection contactor P2 of the connection base, consequently withthe connection terminal T2 of the terminal block.

In the case of the terminal block 10 of the invention, respectively theconnection system formed therewith, consequently in the case of thefield device formed therewith, a first resistance element R1 as well asa second resistance element R2 are arranged within the platform 100.Particularly for the purpose of the forming a switch output conformingto the above mentioned European standard EN 60947-5-6:2000, asschematically presented in FIG. 1, a first connection of the resistanceelement R1, for example, one also embedded in electrically insulating,synthetic material, is electrically connected with the connectionterminal T1 of the terminal block 100 and a second connection of saidresistance element R1 is electrically connected with the connectioncontactor J1 of the terminal block 100. Furthermore, a first connectionof the resistance element R2, for example, one likewise embedded inelectrically insulating, synthetic material, is, such as schematicallypresented in FIG. 1, electrically connected with the connectioncontactor J1 or, such as schematically presented in FIG. 2, with theconnection terminal T1, of the terminal block 100, while a secondconnection of the resistance element R2 is electrically connected bothwith the connection terminal T2 as well as also with the connectioncontactor J2 of the terminal block 100. As a result, the resistanceelement R1 forms a series resistance, which limits electrical currentflowing during operation through the connection terminals T1, T2,consequently electrical current flowing in the circuit output 30A, andthe resistance element R2 forms accordingly a parallel resistanceenabling during operation a permanent electrical current flow in thecircuit output 30A.

In an embodiment of the invention, the resistance element R1 has anohmic resistance of greater than 0.9 kΩ and less than 1.1 kΩ and/or theresistance element R2 has an ohmic resistance of greater than 9 kΩ andless than 11 kΩ. Alternatively or in supplementation, the ohmicresistance of the first resistance element and the ohmic resistancesecond resistance element are, according to an additional embodiment ofthe invention, not least of all also for the purpose of assuring theelectrical current level required in European standard EN 60947-5-6:2000for the switch states corresponding to logic “0”, respectively logic“1”, so selected that, as a result, the resistance element R2 has anohmic resistance, which is greater than 9-times an ohmic resistance ofthe resistance element R1 and less than 11-times the ohmic resistance ofthe resistance element R1.

1-14. (canceled)
 15. A terminal block for electrically connecting aconnection line having at least two conductors, especially a connectionline extending externally of an electronics housing, which terminalblock comprises: a platform composed at least partially of anelectrically insulating, synthetic material, especially a syntheticmaterial having a dielectric strength sufficient to meet Europeanstandard EN 60947-1; a first connection terminal arranged on a firstside of said platform forming a first connection side of the terminalblock and serving for connection of a first conductor of the connectionline; at least a second connection terminal arranged on the first sideof said platform, laterally spaced from said first connection terminaland serving for connection of a second conductor of the connection line;a first connection contactor arranged on a second side of said platformforming a second connection side of said terminal block, especially afirst connection contactor embodied as a contact pin or as a contactjack; a second connection contactor arranged on said second side of saidplatform and laterally spaced from said first connection contactor,especially a second connection contactor embodied as a contact pin or asa contact jack; a first resistance element arranged within saidplatform, especially a first resistance element embedded in syntheticmaterial, wherein a first connection of said first resistance element iselectrically connected with said first connection terminal and a secondconnection of said first resistance element is electrically connectedwith said first connection contactor; as well as a second resistanceelement arranged within the platform, especially a second resistanceelement embedded in synthetic material, wherein a first connection ofsaid second resistance element is electrically connected with said firstconnection terminal or with said first connection contactor and a secondconnection of said second resistance element is electrically connectedboth with said second connection terminal as well as also with saidsecond connection contactor.
 16. The terminal block as claimed in claim15, wherein: said first resistance element has an ohmic resistance ofgreater than 0.9 kΩ and less than 1.1 kΩ; and/or said second resistanceelement has an ohmic resistance of greater than 9 kΩ and less than 11kΩ; and/or said second resistance element has an ohmic resistance, whichis greater than 9 times an ohmic resistance of said first resistanceelement and less than 11 times the ohmic resistance of said firstresistance element.
 17. A connection apparatus for electricallyconnecting a field device circuit, which is accommodated in anelectronics housing, with a connection line extending externally of theelectronics housing, which connection apparatus comprises: a terminalblock as claimed in claim 15 as well as; a connection base for saidterminal block, which connection base is composed at least partially ofan electrically insulating, synthetic material.
 18. The connectionapparatus as claimed in claim 17, wherein: said connection basecomprises: a platform composed at least partially of an electricallyinsulating, synthetic material; a first connection contactor arranged ona first side of said platform forming a first connection side of saidconnection base and complementary to said first connection contactor ofsaid terminal block; as well as at least a second connection contactorarranged on the first side of said platform, laterally spaced from saidfirst connection contactor, and complementary to said second connectioncontactor of said terminal block.
 19. The connection apparatus asclaimed in claim 18, wherein: said connection base and said terminalblock are mechanically connected with one another to form a pluggable,especially releasable, galvanic connection between said first connectioncontactor of said terminal block and said first connection contactor ofsaid connection base as well as between said second connection contactorof said terminal block and said second connection contactor of saidconnection base; and/or each of the two connection contactors of saidconnection base is electrically connected, especially by materialbonding, with a line of an electronic circuit, especially a line formedas a conductive trace on a circuit board.
 20. A field device, especiallya measuring and/or switch device, comprising: a connection apparatus asclaimed in claim 17; and an electronic circuit electrically connectedwith said connection apparatus.
 21. The field device as claimed in claim20, wherein: said electronic circuit has two connection contactorsembodied, especially, in each case, at least sectionally as a conductivetrace on a circuit board and/or at least sectionally as a conductivewire; a first connection contactor is electrically connected with afirst connection contactor of said connection base and a secondconnection contactor is electrically connected with a second connectioncontactor of said connection base, especially by means of solderedconnections.
 22. The field device as claimed in claim 20, furthercomprising: an electronics housing, wherein: both said connectionapparatus as well as also said electronic circuit are accommodatedwithin said electronics housing.
 23. The field device as claimed inclaim 20, further comprising: a measuring transducer for producing atleast one measurement signal dependent on a physical, measured variableto be registered.
 24. The field device as claimed in claim 20, wherein:said electronic circuit has a circuit output, especially one formed bymeans of a transistor and/or passive circuit output, with a first outputcontactor electrically connected with a first connection contactor ofsaid connection base and with a second output contactor electricallyconnected with a second connection contactor of said connection base;especially in such a manner that, by means of the circuit output, saidconnection base and said terminal block, a switch output conforming toEuropean standard EN 60947 5 6:2000 is formed.
 25. The field device asclaimed in claim 20, wherein: said electronic circuit has a bipolartransistor with a collector connection, especially a collectorconnection forming a first connection contactor of said electroniccircuit, and with an emitter connection, especially an emitterconnection forming a second connection contactor of said electroniccircuit.
 26. The field device as claimed in claim 25, wherein:especially for forming a circuit output meeting European standard EN60947 5 6:2000, the collector connection of said bipolar transistor iselectrically connected with a first connection contactor of a connectionbase, consequently via a first resistance element with a firstconnection terminal of a terminal block; and the emitter connection ofsaid bipolar transistor is electrically connected with a secondconnection contactor of a connection base, consequently with a secondconnection terminal of said terminal block.
 27. The field device asclaimed in claim 20, wherein: said electronic circuit has a field effecttransistor with a drain connection, especially a drain connectionforming the first connection contactor of said electronic circuit, andwith a source connection, especially a source connection forming thesecond connection contactor of said electronic circuit.
 28. The fielddevice as claimed in claim 27, wherein: especially for forming a circuitoutput meeting European standard EN 60947 5 6:2000, the drain connectionof the field effect transistor is electrically connected with the firstconnection contactor of the connection base, consequently via firstresistance element with the first connection terminal of the terminalblock; and the source connection of the field effect transistor iselectrically connected with the second connection contactor of theconnection base, consequently with the second connection terminal of theterminal block.